Funding for this research was provided by:
Fundação de Amparo à Pesquisa do Estado de São Paulo (2018/08631-3)
Received: 31 August 2020
Accepted: 29 December 2020
First Online: 9 January 2021
Ethics approval and consent to participate
: The study was approved by the local review board (Comissão de Ética para Análise de Projetos de Pesquisa, (CAPPesq), ethic approval number. 166.642/2012). A signed informed consent was provided by all participants who agreed to participate in the study prior to the interviews and blood collection.
: Not applicable.
: The author(s) declare no competing interests.